include/vlc_aout.h

   1 /*****************************************************************************
   2  * vlc_aout.h : audio output interface
   3  *****************************************************************************
   4  * Copyright (C) 2002-2011 the VideoLAN team
   5  *
   6  * Authors: Christophe Massiot <massiot@via.ecp.fr>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 #ifndef VLC_AOUT_H
  24 #define VLC_AOUT_H 1
  25
  26 /**
  27  * \file
  28  * This file defines functions, structures and macros for audio output object
  29  */
  30
  31 /* Max number of pre-filters per input, and max number of post-filters */
  32 #define AOUT_MAX_FILTERS                10
  33
  34 /* Buffers which arrive in advance of more than AOUT_MAX_ADVANCE_TIME
  35  * will be considered as bogus and be trashed */
  36 #define AOUT_MAX_ADVANCE_TIME           (AOUT_MAX_PREPARE_TIME + CLOCK_FREQ)
  37
  38 /* Buffers which arrive in advance of more than AOUT_MAX_PREPARE_TIME
  39  * will cause the calling thread to sleep */
  40 #define AOUT_MAX_PREPARE_TIME           (2 * CLOCK_FREQ)
  41
  42 /* Buffers which arrive after pts - AOUT_MIN_PREPARE_TIME will be trashed
  43  * to avoid too heavy resampling */
  44 #define AOUT_MIN_PREPARE_TIME           AOUT_MAX_PTS_ADVANCE
  45
  46 /* Tolerance values from EBU Recommendation 37 */
  47 /** Maximum advance of actual audio playback time to coded PTS,
  48  * above which downsampling will be performed */
  49 #define AOUT_MAX_PTS_ADVANCE            (CLOCK_FREQ / 25)
  50
  51 /** Maximum delay of actual audio playback time from coded PTS,
  52  * above which upsampling will be performed */
  53 #define AOUT_MAX_PTS_DELAY              (3 * CLOCK_FREQ / 50)
  54
  55 /* Max acceptable resampling (in %) */
  56 #define AOUT_MAX_RESAMPLING             10
  57
  58 #include "vlc_es.h"
  59
  60 #define AOUT_FMTS_IDENTICAL( p_first, p_second ) (                          \
  61     ((p_first)->i_format == (p_second)->i_format)                           \
  62       && AOUT_FMTS_SIMILAR(p_first, p_second) )
  63
  64 /* Check if i_rate == i_rate and i_channels == i_channels */
  65 #define AOUT_FMTS_SIMILAR( p_first, p_second ) (                            \
  66     ((p_first)->i_rate == (p_second)->i_rate)                               \
  67       && ((p_first)->i_physical_channels == (p_second)->i_physical_channels)\
  68       && ((p_first)->i_original_channels == (p_second)->i_original_channels) )
  69
  70 #define VLC_CODEC_SPDIFL VLC_FOURCC('s','p','d','i')
  71 #define VLC_CODEC_SPDIFB VLC_FOURCC('s','p','d','b')
  72
  73 #define AOUT_FMT_NON_LINEAR( p_format )                 \
  74     ( ((p_format)->i_format == VLC_CODEC_SPDIFL)       \
  75        || ((p_format)->i_format == VLC_CODEC_SPDIFB)   \
  76        || ((p_format)->i_format == VLC_CODEC_A52)       \
  77        || ((p_format)->i_format == VLC_CODEC_DTS) )
  78
  79 /* This is heavily borrowed from libmad, by Robert Leslie <rob@mars.org> */
  80 /*
  81  * Fixed-point format: 0xABBBBBBB
  82  * A == whole part      (sign + 3 bits)
  83  * B == fractional part (28 bits)
  84  *
  85  * Values are signed two's complement, so the effective range is:
  86  * 0x80000000 to 0x7fffffff
  87  *       -8.0 to +7.9999999962747097015380859375
  88  *
  89  * The smallest representable value is:
  90  * 0x00000001 == 0.0000000037252902984619140625 (i.e. about 3.725e-9)
  91  *
  92  * 28 bits of fractional accuracy represent about
  93  * 8.6 digits of decimal accuracy.
  94  *
  95  * Fixed-point numbers can be added or subtracted as normal
  96  * integers, but multiplication requires shifting the 64-bit result
  97  * from 56 fractional bits back to 28 (and rounding.)
  98  */
  99 typedef int32_t vlc_fixed_t;
 100 #define FIXED32_FRACBITS 28
 101 #define FIXED32_MIN ((vlc_fixed_t) -0x80000000L)
 102 #define FIXED32_MAX ((vlc_fixed_t) +0x7fffffffL)
 103 #define FIXED32_ONE ((vlc_fixed_t) 0x10000000)
 104
 105 /*
 106  * Channels descriptions
 107  */
 108
 109 /* Values available for physical and original channels */
 110 #define AOUT_CHAN_CENTER            0x1
 111 #define AOUT_CHAN_LEFT              0x2
 112 #define AOUT_CHAN_RIGHT             0x4
 113 #define AOUT_CHAN_REARCENTER        0x10
 114 #define AOUT_CHAN_REARLEFT          0x20
 115 #define AOUT_CHAN_REARRIGHT         0x40
 116 #define AOUT_CHAN_MIDDLELEFT        0x100
 117 #define AOUT_CHAN_MIDDLERIGHT       0x200
 118 #define AOUT_CHAN_LFE               0x1000
 119
 120 /* Values available for original channels only */
 121 #define AOUT_CHAN_DOLBYSTEREO       0x10000
 122 #define AOUT_CHAN_DUALMONO          0x20000
 123 #define AOUT_CHAN_REVERSESTEREO     0x40000
 124
 125 #define AOUT_CHAN_PHYSMASK          0xFFFF
 126 #define AOUT_CHAN_MAX               9
 127
 128 /* Values used for the audio-device and audio-channels object variables */
 129 #define AOUT_VAR_MONO               1
 130 #define AOUT_VAR_STEREO             2
 131 #define AOUT_VAR_2F2R               4
 132 #define AOUT_VAR_3F2R               5
 133 #define AOUT_VAR_5_1                6
 134 #define AOUT_VAR_6_1                7
 135 #define AOUT_VAR_7_1                8
 136 #define AOUT_VAR_SPDIF              10
 137
 138 #define AOUT_VAR_CHAN_STEREO        1
 139 #define AOUT_VAR_CHAN_RSTEREO       2
 140 #define AOUT_VAR_CHAN_LEFT          3
 141 #define AOUT_VAR_CHAN_RIGHT         4
 142 #define AOUT_VAR_CHAN_DOLBYS        5
 143
 144 /*****************************************************************************
 145  * Main audio output structures
 146  *****************************************************************************/
 147
 148 #define aout_BufferFree( buffer ) block_Release( buffer )
 149
 150 /* Size of a frame for S/PDIF output. */
 151 #define AOUT_SPDIF_SIZE 6144
 152
 153 /* Number of samples in an A/52 frame. */
 154 #define A52_FRAME_NB 1536
 155
 156 /* FIXME to remove once aout.h is cleaned a bit more */
 157 #include <vlc_block.h>
 158
 159 typedef int (*aout_volume_cb) (audio_output_t *, float, bool);
 160
 161 /** Audio output object */
 162 struct audio_output
 163 {
 164     VLC_COMMON_MEMBERS
 165
 166     audio_sample_format_t format; /**< Output format (plugin can modify it
 167         only when succesfully probed and not afterward) */
 168
 169     struct aout_sys_t *sys; /**< Output plugin private data */
 170     void (*pf_play)(audio_output_t *, block_t *); /**< Audio buffer callback */
 171     void (* pf_pause)( audio_output_t *, bool, mtime_t ); /**< Pause/resume
 172         callback (optional, may be NULL) */
 173     void (* pf_flush)( audio_output_t *, bool ); /**< Flush/drain callback
 174         (optional, may be NULL) */
 175     aout_volume_cb          pf_volume_set; /**< Volume setter (or NULL) */
 176 };
 177
 178 /**
 179  * It describes the audio channel order VLC expect.
 180  */
 181 static const uint32_t pi_vlc_chan_order_wg4[] =
 182 {
 183     AOUT_CHAN_LEFT, AOUT_CHAN_RIGHT,
 184     AOUT_CHAN_MIDDLELEFT, AOUT_CHAN_MIDDLERIGHT,
 185     AOUT_CHAN_REARLEFT, AOUT_CHAN_REARRIGHT, AOUT_CHAN_REARCENTER,
 186     AOUT_CHAN_CENTER, AOUT_CHAN_LFE, 0
 187 };
 188
 189 /*****************************************************************************
 190  * Prototypes
 191  *****************************************************************************/
 192
 193 /**
 194  * This function computes the reordering needed to go from pi_chan_order_in to
 195  * pi_chan_order_out.
 196  * If pi_chan_order_in or pi_chan_order_out is NULL, it will assume that vlc
 197  * internal (WG4) order is requested.
 198  */
 199 VLC_API int aout_CheckChannelReorder( const uint32_t *pi_chan_order_in, const uint32_t *pi_chan_order_out, uint32_t i_channel_mask, int i_channels, int *pi_chan_table );
 200 VLC_API void aout_ChannelReorder( uint8_t *, int, int, const int *, int );
 201
 202 /**
 203  * This fonction will compute the extraction parameter into pi_selection to go
 204  * from i_channels with their type given by pi_order_src[] into the order
 205  * describe by pi_order_dst.
 206  * It will also set :
 207  * - *pi_channels as the number of channels that will be extracted which is
 208  * lower (in case of non understood channels type) or equal to i_channels.
 209  * - the layout of the channels (*pi_layout).
 210  *
 211  * It will return true if channel extraction is really needed, in which case
 212  * aout_ChannelExtract must be used
 213  *
 214  * XXX It must be used when the source may have channel type not understood
 215  * by VLC. In this case the channel type pi_order_src[] must be set to 0.
 216  * XXX It must also be used if multiple channels have the same type.
 217  */
 218 VLC_API bool aout_CheckChannelExtraction( int *pi_selection, uint32_t *pi_layout, int *pi_channels, const uint32_t pi_order_dst[AOUT_CHAN_MAX], const uint32_t *pi_order_src, int i_channels );
 219
 220 /**
 221  * Do the actual channels extraction using the parameters created by
 222  * aout_CheckChannelExtraction.
 223  *
 224  * XXX this function does not work in place (p_dst and p_src must not overlap).
 225  * XXX Only 8, 16, 24, 32, 64 bits per sample are supported.
 226  */
 227 VLC_API void aout_ChannelExtract( void *p_dst, int i_dst_channels, const void *p_src, int i_src_channels, int i_sample_count, const int *pi_selection, int i_bits_per_sample );
 228
 229 /* */
 230 static inline unsigned aout_FormatNbChannels(const audio_sample_format_t *fmt)
 231 {
 232     return popcount(fmt->i_physical_channels & AOUT_CHAN_PHYSMASK);
 233 }
 234
 235 VLC_API unsigned int aout_BitsPerSample( vlc_fourcc_t i_format ) VLC_USED;
 236 VLC_API void aout_FormatPrepare( audio_sample_format_t * p_format );
 237 VLC_API void aout_FormatPrint(vlc_object_t *, const char *,
 238                               const audio_sample_format_t *);
 239 #define aout_FormatPrint(o, t, f) aout_FormatPrint(VLC_OBJECT(o), t, f)
 240 VLC_API const char * aout_FormatPrintChannels( const audio_sample_format_t * ) VLC_USED;
 241
 242 VLC_API void aout_VolumeNoneInit( audio_output_t * );
 243 VLC_API void aout_VolumeSoftInit( audio_output_t * );
 244 VLC_API void aout_VolumeHardInit( audio_output_t *, aout_volume_cb );
 245 VLC_API void aout_VolumeHardSet( audio_output_t *, float, bool );
 246
 247 VLC_API int aout_ChannelsRestart( vlc_object_t *, const char *, vlc_value_t, vlc_value_t, void * );
 248
 249 /* */
 250 VLC_API vout_thread_t * aout_filter_RequestVout( filter_t *, vout_thread_t *p_vout, video_format_t *p_fmt ) VLC_USED;
 251
 252 /** Audio output buffer FIFO */
 253 struct aout_fifo_t
 254 {
 255     aout_buffer_t *         p_first;
 256     aout_buffer_t **        pp_last;
 257     date_t                  end_date;
 258 };
 259
 260 /* Legacy packet-oriented audio output helpers */
 261 typedef struct
 262 {
 263     vlc_mutex_t lock;
 264     aout_fifo_t partial; /**< Audio blocks before packetization */
 265     aout_fifo_t fifo; /**< Packetized audio blocks */
 266     mtime_t pause_date; /**< Date when paused or VLC_TS_INVALID */
 267     unsigned samples; /**< Samples per packet */
 268     bool starving; /**< Whether currently starving (to limit error messages) */
 269 } aout_packet_t;
 270
 271 VLC_API void aout_PacketInit(audio_output_t *, aout_packet_t *, unsigned);
 272 VLC_API void aout_PacketDestroy(audio_output_t *);
 273
 274 VLC_API void aout_PacketPlay(audio_output_t *, block_t *);
 275 VLC_API void aout_PacketPause(audio_output_t *, bool, mtime_t);
 276 VLC_API void aout_PacketFlush(audio_output_t *, bool);
 277
 278 VLC_API block_t *aout_PacketNext(audio_output_t *, mtime_t) VLC_USED;
 279
 280
 281 #endif /* VLC_AOUT_H */